Conventionally, in a developing apparatus for use in a system configured to form a resist pattern on a substrate, there is performed a series of processes of attracting and holding a semiconductor wafer (hereinafter, simply referred to as “wafer”) used as the substrate by a substrate holding unit provided in a cylindrical cup body, supplying a developing liquid onto a surface of the wafer from a developing liquid nozzle, cleaning the wafer by supplying a cleaning liquid from a cleaning nozzle while rotating the wafer, and drying the wafer by scattering.
At this time, by performing the liquid processings by supplying the processing liquids onto the wafer while evacuating the inside of the cup body through an exhaust port opened in the cup body, mist or particles generated by the scattering of the processing liquids can be suppressed from adhering to the wafer.
Recently, as devices are miniaturized, there has been a demand for a higher detergency after a developing processing. The present inventor has investigated a method of performing the cleaning while spinning the wafer at a high speed of, e.g., 4000 rpm. If the RPM of the wafer is increased, however, the cleaning liquid may be easily scattered from the wafer. In such a case, the liquid-scattering of the cleaning liquid scattered back from the cup body may be increased, or the amount of the mist of the cleaning liquid scattered from the wafer may also be increase, so that there is a problem that the amount of mist reattached to the surface of the wafer is increased.
Patent Document 1 describes a technique of suppressing a liquid-scattering back to a substrate and reattachment of mist thereto. In this technique, however, a rotational speed of a wafer is about 2500 rpm, and this method does not mention anything about a case where the RPM of the wafer is higher than this.
Further, Patent Document 2 discloses a technique of cleaning an inside of a cup body by allowing a cleaning liquid scattered form a wafer to flow along an inner surface of the cup body to suppress contamination of the wafer by mist adhering to the cup body. This technique, however, is not directed to suppressing a liquid-scattering back to the wafer and reattachment of mist to the wafer.                Patent Document 1: Japanese Patent Laid-open Publication No. 2010-206019        Patent Document 2: Japanese Patent Laid-open Publication No. 2015-176996        